Electric heater



May 20, 1924. 1,494,939

c. c. ABBo'r-r ELECTRIC HEATER Filed Sept. 23, 1922! Iwentcr; Charles-C.^bbott,

by MMX His At orn'ey.

Patented vmy 2o, 1924. i

UNITED STATES PATENT oFFlcE.

CHARLES C. ABBOTT, OF PITTBFIELD, HASSACHUSETTS, ASSIGNOB T0 GENERALELECTRIC COIPANY, A CORPORATION OF NEW YORK.

ELECTRIC mman.

`Application tiled September 23, 1922. Serial No. 590,020.

To all whom it 'may concern.'

. 'Be it known thatl I, CHARLES C. Annorr'r, a citizen of the UnitedStates, residin at Pittsfield, in 4the county of Berkshire, tateof.Massachusetts, have. invented certain new and useful Improvements inElectric If'leaters, of which the following is a specification.

My invention relates to electric heaters and has for its object theprovision of a sim le, rugged and compact electric heater.

y invention has utility in various heating applications, for example, itmay be used as an air or space heater or 1t may be clamped on orotherwise secured to an object to be heated. v

In carrying out my inventlon I employ a sheath Wire heating unit, forexample, of the type forming the subject matter of my copendingapplication Serial No: 549,63t3, filed April 4, 1922. In heating unitso'this type the resistance conductor is embedded 1n a compacted mass ofinsulating material enclosed in a metallic containing sheath. In oneform of my invention I provide longitudinal heat dissipating vanesassociated with the containing sheath whereb the heat generated in theunit may be quic l transferred either to the air or to the o ject to beheated.

For a better understanding of myinvention reference should be had to theaccompanying drawing iii-which Fig. 1 is an elevation View of anelectric heater embodying my invention; Fig. 2 is a section vievs7 alongthe line 2-2 of Fig. 1 looking in the direction of the arrows; Fig. 3 isa view of a modified form of my invention; Fig. 4 is an elevation Viewof Fig. 3 5 While Fig. 5 is a section view along the line 5 5 of Fig. 4looking in the direction of the arrows.

Referring to Figs. 1 and 2 of the drawing, the electric heater 10 in oneform of my invention comprises a helical coil sheath wire heating unit11, such as that forming the subject matter o my aforesaid copendingapplication. This heating unit in general comprises a helical resistanceconductor 12 embedded in a compacted mass of insulating material 13,such as magnesium oxide, the whole being enclosed by a metalliccontaining sheath 14. This insulating material not only serves toinsulate the resistance l conductor but acts also as a good heatconductor between the resistance con- .tendin ductor and the sheath.Connected to the ends of the resistance conductor are the terminals 11land 11b which project from the ends of the sheath in insulated relationtherewith. The heating unit 11 is clamped between two metallic plates 15and 16 exlongitudinally thereof, the plates being ormed with registeringcentral longitudinal grooves or recesses 15 and 16 respectively in whichthe heatin unit is secured. These plates are'welde together as near theheating unit as ssible so as to clamp the heat-ing unittigliitly. Thewelding of the plates may be accomplished in any suitable manner such asby the line welding or spot welding-process.

The pla-tes 15 and 16 extend throughout substantially the full length ofthe heating unit 11 and it will be observed form two longitudinal heat,dissipating vanes 17 and 18 extending along opposite sides of theheating unit. Due to the fact that the plates 15 and 16 areclampedtightly on the metallic enclosing sheath 14, an intimate thermalrelation is secured between the heating unit and the heat dissipatingvanes so that heat generated in the unit will be quickly transmitted tothe vanes. This heater is particularly adapted for use as an air orspace heater in which application it may be mounted with the vanes 17and 18 in a vertical position so as to facilitate the circulation of airaround the vanes. Apertures 19 may be provided in the vanes 17 and 18 bymeans of which the heater can be secured to a suitable support, forexample, by screws or bolts. The heater may also be similarly secured orclamped on to an object so as to heat the object, the object serving asthe support for the heater.

In the modified form of my invention shown in Figs. 3, 4 and 5 one ofthe clamping plates, for example, 16, is in the shape of a channelmember, it being fiat, and having its longitudinal edges bent over toprovide for greater strength in a lateral direction. In this form of myinvention only one longitudinal recess for the heating unit is provided,this recess 15 being formed in the plate 15 and having a depthsubstantially equal to the diameter of the heating l to the object so asto be in good thermal relation therewith. The ends; of the heating unitcarrying the terminals are preferably' bent away from the plane of theouter face or clamping surface of plate 16 so as to be ont of the waywhen the heater is secured to the object to be heated, and also tofaveilitate the connection of the terminals to a suitable electricalsupply source. The heater may be secured` ,by suitable bolts or screwspassing through the apertures 19. Obviously this forml of lmy inventioncan be used also as a space or air heater as described in connectionwith Figs. 1 and 2.

I have thus provided an exceedingly compact, rugged and economicalheater which has many applications and whichis particularly adapted foruse as a space or air heater or as a heater for various objects byclamping it onto the object. The construction and arrangement'of theheater offers considerable economy7 in manufacture, sol

that it can be-produced at relatively low.

cost. Also by providing longitudinal rather than circumferential heatdissipating vanes so that the heater is flat, the heater occupies andhence may be fitted in a very limited space.

Since one of the characteristics of heating units of the sheath wiretype, such as used for the heating unit 11, is that they can be bent orshaped into any desired form, obviously the electric Aheaters embodyingmy present invention may be readily formed into any desired shape so asto fit the space or object to be heated.

While I have described my invention as embodied Ln concrete form and asoperating in a specific manner in accordance with the provisions of thepatent statutes, it should be understood that I do not limit myinvention thereto, since Various modifications thereof will suggest'themselves to those skilled in the art without departing from thespirit of my invention, the scope of which is setr forth in the annexedclaims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. An electric heater comprising a metallic sheath, a which said s eathis clamped in good heat conducting relation therewith, said platesforming heat dissipating vanes for said sheath, a resistance conductorin said sheath, and granular insulating material embedding saidresistance conductor so that heat is readily conducted to said sheathland heat dissipating vanes.

2. An electric heater comprising a metallic sheath, a pair ofmetallicplates one of which is provided with a longitudinal recess in which saidmetallic sheath is clamped by the other in good heat conducting relationwith said plates, said plates being joined together so as to formlongitudinal heat dissipating vanes for said sheath, a helicalresistance conductor in said sheath, and

Agranular insulating material compacted to a'hard dense mass in saidsheath so that heat is readily conducted to said sheath and heatdissipating vanes.

l3. An electric heater comprising a metallic sheath, a metallic plateprovided with a longitudinal groove for said sheath, a second plateforming a clamping surface securing said sheath in said groove in goodheat conducting relation with said plates, said plates being connectedtogether so as to form longitudinal heat dissipating vanes for saidsheath, a helical resistance conductor in said sheath, and granularinsulating material compacted to a hard dense mass in said sheath sothat heat is readily conducted to said sheath and heat dissipatingvanes.

In witness whereof, I have hereunto set my hand lthis 16th day ofSeptember, 1922.

CHARLES C. ABBOTT.-

pair of metallic plates between

